Bio Filter

you should definitely be using the bio filter, although whether to use the old one or not I will leave to the more experinced people on the forums

in my opinon though, I would think to use the bio filter that was in it since it might have the good bacteria colonies still in it if it hasn't been scoured clean. Otherwise start from scratch with a new bio filter and start cycling that puppy so you can get some fish in there

have fun

It doesn't really matter much about the Bio-Foam iin the Whisper filter. I have worked with these thing so long I know them inside and out. The old filters (models E, J, C, 1, 2, 3, 4, and 5) did not have any Bio Foam. Tetra/Willinger/SecondNature clearly states in the manual (for models Triad 1000, 2000, and 3000) that the Bio Foam is your first source of Bio Media and that the Aerobic Frame (if you use it instead of the single packs of Pre- Assembled Bio-Bags) is your secondary source. You should use your Bio-Foam but if you don't, you will always have Bio 'Stuff' all over your tank and especially in the filter box, WonderTube (intake tube), and Energizer (motor) Well. Just don't clean the filter box too much. Also, if you have the old smoke/clear colored filters, you can see the bio stuff growing in the filter box. :idea:

If its been out for a while (more than an hour if not in water, 8 hours if kept it water) it should be very well cleaned or replaced. You don't want dead bacteria to decompose in your tank. I had that happen once, smelled terible.